A variety of materials are chosen to make parts composing electronic equipment, such as a copier or a printer, with considerations to the characteristics or functions required of the parts. For example, polycarbonate (PC) resins, acrylonitrile-butadiene-styrene (ABS) resins, and PC/ABS resins are generally used in quantities to make parts that house and protect, e.g., a driving part of electronic equipment, as described in patent document 1 below. These resins are produced through reactions of petroleum-derived compounds.
Fossil resources such as petroleum, coal, and natural gas are composed mainly of carbon fixed in soil for long periods of time. On combusting a fossil resource or a product derived from a fossil resource, carbon dioxide is released into the air. That is, carbon that does not essentially exist in the air but is fixed deep in soil is released abruptly in the form of carbon dioxide to greatly increase carbon dioxide in the air, which is said to be a cause of global warming. Although ABS, PC, and other petroleum-derived resins have excellent characteristics as materials of electronic equipment parts, it is desirable to reduce use of such petroleum-derived resins from the viewpoint of prevention of global warming.
On the other hand, plant-derived resins are the results of photosynthesis in plants starting with carbon dioxide in the air and water. There is a concept that the carbon dioxide released from burning plant-derived resins corresponds to the carbon dioxide that originally existed in the atmosphere so that the net carbon balance is “zero”, eventually resulting in no increase in total atmospheric carbon dioxide. Based on this concept, plant-derived resins are called carbon-neutral materials. It is now imperative to use carbon neutral materials in place of petroleum derived resins in view of the global warming issue.
Patent document 2 (see below) discloses a PC resin obtained from petroleum-derived materials a part of which is replaced with a plant-derived material such as starch so as to reduce the use of the petroleum resource. Aiming to develop a more near-perfect carbon-neutral material, further improvements have been sought.